(1) Field of the Invention
This invention relates to immunochemicals for use with microbial pesticides. More particularly this invention is for monoclonal antibodies to crystal proteins of Bacillus thuringiensis subsp. israelensis and to the hybrid cell lines that secrete these monospecific antibodies.
(2) Description of the Prior Art
Bacillus thuringiensis is an aerobic, endospore-forming, Gram positive bacterium which forms a proteinaceous crystalline inclusion during sporulation and is pathogenic to certain insects. Monoclonal antibodies to Bacillus thuringiensis have been reported for crystal protein only of subsp. thuringiensis and kurstaki (Huber-Lukac et al., 1982, 1983, 1986). The crystal protein of B. thuringiensis subsp. israelensis is larvicidal to several families of Dipteran insects, including mosquitoes, black flies, midges, and horn flies (Temeyer 1984). Crystals prepared from B. thuringiensis subsp. israelensis contain several proteins and there is some controversy over which of these component proteins represents the insecticidal toxin (delta-endotoxin) active in vivo. Molecular biological techniques are capable of resolving this controversy, but are complicated by potential proteolysis of crystal protein components during preparation as well as difficulty in assaying insecticidal activity of soluble proteins.
One method of production of monoclonal antibodies by the fusion of spleen cells from immunized mice and myeloma cells grown in continuous culture has been described previously by Zola & Brooks (1982). However, it should be noted that preparation of hybridoma cell populations remains unpredictable, and one cannot extrapolate from one antigen or cell system to another.
Heretofore, monoclonal antibodies specific for different component proteins of B. thuringiensis subsp. israelensis crystals were not available.